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Backflow Preventer 3/4" FHT x 3/4" MPT

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The 3/4" FNPT plastic back-flow preventer (anti-siphon valve) from Hendrickson Bros is an effective and economical way to eliminate the risk of back-flow contamination from an outdoor pipe or other water outlet with pipe threads. Constructed of high-strength ABS plastic the back-flow preventer is made of corrosion resistant material with outstanding reliability and long life. The devises are laboratory tested and industry approved since 1984.

The 3/4" plastic back-flow preventer (anti-siphon valve) from Hendrickson Bros is available in 3/4" with female hose thread or pipe thread. The back-flow device is installed at the beginning of a drip irrigation system and is used to prevent water from back siphoning into the water supply line. The back-flow device should always be used when applying fertilizer and when applying fertilizer the back-flow device should be the first item installed after the faucet. Install it with a pressure regulator with hose or pipe thread.

Important: This type of back-flow device (vacuum breaker) cannot be used under continuous pressure.
Codes do not permit the use of this device under continuous pressure as the back-flow device can stop functioning in emergency conditions. If used under constant pressure, the back-flow device can crack and fail due to a pressure surge when downstream valves close. Some municipalities or local water districts require the use of back-flow device/atmospheric vacuum breakers. Make sure to check your local city code to see if you need to install this device.

By: gottwig, 07/30/12

Went through three of these before trying the heavy duty model. Kept cracking at the hose thread side even when left loosely attached.

The Drip Store ~ response by: Cameron, 07/30/12

Backflow device A016 is a FHT x MNPT (pipe thread) model. Attempting to tighten this part's male side (MNPT) to a FHT device could damage the items, and leakage will almost certainly occour even without over-tightening. Do not use teflon tape on the FHT side, since hose thread items use a seat washer. As always, The Drip Store stands behind our part quality and we will replace suspected defective items in accordance with our published returns policy. We would encourage this customer to contact our representatives for troubleshooting help and, if determined to be defective, complete replacement of these devices.

By: Aaron Winter, 04/30/05

No problems with this item over past year and a half.
Does not leak (except when shutting water off which is what it is supposed to do to prevent a backflow)